PROJECT SUMMARY/ABSTRACT The inter-disciplinary ?Training Program in Cancer Research? at Fox Chase Cancer Center, currently in its 40th year, focuses on preparing a cadre of outstanding cancer scientists through rigorous research and impactful, targeted mentoring. Continued funds are requested to support 10 postdoctoral trainees. The highly collaborative participating faculty consist of 50 Cancer Center members of the Fox Chase Cancer Center and Temple Health. Collectively, these faculty possess interests that span the cancer spectrum, including cell growth control, signal transduction, inflammation, epigenetics, cancer prevention, bio-behavioral cancer research, and developmental therapeutics. The postdoctoral pool is extremely strong; there is an average of 3-4 applicants per open slot, and the majority of applicants received graduate training at outstanding institutions, and published in high-impact journals. The program offers diverse training in areas relevant to cancer research, with a combination of didactic and laboratory-based training, including seminar series and journal clubs, scientific writing courses, career development seminars, and individualized development plans. Input from the postdoctoral pool is extensive and highly valued in shaping this program; trainee satisfaction is best exemplified by our long-standing placement in the Top 20 ?Best Places in the United States for Postdoctoral Training?, as published in The Scientist magazine (through 2012). Trainee slots are highly competitive, all slots have been continuously filled for the last 3 funding cycles, and >75% of trainees who have completed training report that they are still doing research directly relevant to cancer. Appointments are made for one year, with an option to renew for a second year of support. A chief objective of our Research Training Plan is to equip our trainees with the skills needed to transition to impactful careers in cancer biology and medicine, recognizing that fundamental contributions to the cancer effort can be achieved in a wide array of career paths. In summary, this proposal continues a long history of excellence in training in cancer biology at Fox Chase.